ISPN-4621 MassIndexer does not work on replicated cache (with local inde...

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https://issues.jboss.org/browse/ISPN-4621

* Refactored MassIndexer to be based upon distributed executors rather than MapReduce
* Depending on the index configuration and on the cache mode, executes a clean/flush per node or clean/flush per mass index execution
* No extra config on query or Mass Indexer itself needed
* Works for clustered queries, sharding, different entities sharing the same index and different entities sharing the same cache but on different indexes